Reversed mode spin torque oscillator with shaped field generation layer

ABSTRACT

The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 16/368,550 filed on Mar. 28, 2019, which application claimsbenefit of U.S. Provisional Patent Application Ser. No. 62/674,581,filed May 21, 2018, both of which are herein incorporated by reference.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

Embodiments of the present disclosure generally relate to data storagedevices, and more specifically, to a magnetic media drive employing amagnetic recording head.

Description of the Related Art

Over the past few years, microwave assisted magnetic recording (MAMR)has been studied as a recording method to improve the areal density of amagnetic read/write device, such as a hard disk drive (HDD). MAMRenabled magnetic recording heads utilize a MAMR stack disposed betweenthe trailing shield and the main pole to improve write field and/orfield gradient, leading to better areal density capability (ADC). TheMAMR stack may be a spin torque oscillator (STO) for generating amicrowave (high frequency AC magnetic field). When a bias current isconducted to the STO from the trailing shield, the STO oscillates andprovides an AC magnetic field to the recording medium. The AC magneticfield may reduce the coercive force of the recording medium, thus highquality recording by MAMR may be achieved. Typically the STO includes aspin polarization layer (SPL) for transmitting the spin polarizedtorque, a field generation layer (FGL) for generating the AC magneticfield, and an interlayer disposed between the SPL and the FGL. The FGLis located proximate to the trailing shield, and the SPL is locatedproximate to the main pole.

However, the trailing shield, or a trailing shield hot seed layer, canhave a negative magnetic effect on the FGL due to the proximity to theFGL. Furthermore, since the SPL is aligned to the main pole, currentefficiency from the trailing shield to the STO is low due to currentcrowding.

Therefore, there is a need in the art for an improved MAMR enabledmagnetic head.

SUMMARY OF THE DISCLOSURE

The present disclosure generally relates to data storage devices, andmore specifically, to a magnetic media drive employing a magneticrecording head. The head includes a trailing shield, a main pole, an STOdisposed between the trailing shield and the main pole, and anon-magnetic conductive structure adjacent to the main pole and incontact with the STO. The STO includes an FGL and an SPL, and the FGL isdisposed between the main pole and the SPL. The FGL includes a sideextending over the main pole and at least a portion of the non-magneticconductive structure. With the FGL disposed proximate to the main poleand over at least a portion of the non-magnetic conductive structure,current crowding and disturbance from the trailing shield are minimized.

In one embodiment, a magnetic recording head includes a main pole, and aspin torque oscillator in contact with the main pole. The spin torqueoscillator includes a spin polarization layer and a field generationlayer disposed between the spin polarization layer and the main pole.The field generation layer includes a surface at a media facing surface,and the surface has a trapezoidal shape. The magnetic recording headfurther includes a non-magnetic conductive structure surrounding atleast a portion of the main pole, and the non-magnetic conductivestructure is in contact with the spin torque oscillator.

In another embodiment, a magnetic recording head includes a main pole,and a spin torque oscillator in contact with the main pole. The spintorque oscillator includes a spin polarization layer and a fieldgeneration layer disposed between the spin polarization layer and themain pole. The field generation layer includes a surface at a mediafacing surface, and the surface includes a first side facing the mainpole and a second side facing the spin polarization layer. The firstside has a length that is substantially greater than a length of thesecond side. The magnetic recording head further includes a non-magneticconductive structure surrounding at least a portion of the main pole,and the first side of the field generation layer is disposed over atleast a portion of the non-magnetic conductive structure.

In another embodiment, a magnetic recording head includes a main pole,and a spin torque oscillator in contact with the main pole. The spintorque oscillator includes a spin polarization layer and a fieldgeneration layer disposed between the spin polarization layer and themain pole. The field generation layer includes a surface at a mediafacing surface, and the surface includes a first side facing the mainpole, a second side facing the spin polarization layer, a third sideconnecting the first side and the second side, and a fourth sideopposite the third side. The first side forms a first acute angle withthe third side. The magnetic recording head further includes anon-magnetic conductive structure surrounding at least a portion of themain pole, and the non-magnetic conductive structure is in contact withthe spin torque oscillator.

In another embodiment, a magnetic recording head includes a leadingshield, a trailing shield, a main pole having a surface at a mediafacing surface, wherein the surface includes a side, a spin torqueoscillator in contact with the side of the main pole, wherein the spintorque oscillator includes a spin polarization layer and a fieldgeneration layer. The magnetic recording head further includes anon-magnetic conductive structure surrounding at least a portion of themain pole, a first current source connected to the main pole and thetrailing shield, and a second current source connected to the main poleand the leading shield.

In another embodiment, a magnetic recording head includes a leadingshield, a trailing shield, a main pole having a surface at a mediafacing surface, wherein the surface includes a side, a non-magneticconductive layer disposed between the trailing shield and the main pole,a spin torque oscillator in contact with the side of the main pole,wherein the spin torque oscillator comprises a spin polarization layerand a field generation layer. The magnetic recording head furtherincludes a non-magnetic conductive structure surrounding at least aportion of the main pole, and a current source configured to flow afirst current from the main pole to the trailing shield through the spintorque oscillator and a second current from the main pole to thetrailing shield through the non-magnetic conductive layer.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 is a schematic illustration of a magnetic media device accordingto one embodiment.

FIG. 2 is a fragmented, cross-sectional side view of a MAMR read/writehead facing a magnetic disk according to one embodiment.

FIG. 3 is a MFS view of a portion of a write head of FIG. 2 according toone embodiment.

FIGS. 4A-4C are MFS views of an STO of the write head of FIG. 2according to one embodiment.

FIGS. 5A-5D are cross-sectional side views of the write head of FIG. 2according to one embodiment.

FIGS. 6A-6C are cross-sectional side views of the write head of FIG. 2according to another embodiment.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation.

DETAILED DESCRIPTION

In the following, reference is made to embodiments of the disclosure.However, it should be understood that the disclosure is not limited tospecific described embodiments. Instead, any combination of thefollowing features and elements, whether related to differentembodiments or not, is contemplated to implement and practice thedisclosure. Furthermore, although embodiments of the disclosure mayachieve advantages over other possible solutions and/or over the priorart, whether or not a particular advantage is achieved by a givenembodiment is not limiting of the disclosure. Thus, the followingaspects, features, embodiments and advantages are merely illustrativeand are not considered elements or limitations of the appended claimsexcept where explicitly recited in a claim(s). Likewise, reference to“the disclosure” shall not be construed as a generalization of anyinventive subject matter disclosed herein and shall not be considered tobe an element or limitation of the appended claims except whereexplicitly recited in a claim(s).

The present disclosure generally relates to data storage devices, andmore specifically, to a magnetic media drive employing a magneticrecording head. The head includes a trailing shield, a main pole, an STOdisposed between the trailing shield and the main pole, and anon-magnetic conductive structure adjacent to the main pole and incontact with the STO. The STO includes an FGL and an SPL, and the FGL isdisposed between the main pole and the SPL. The FGL includes a sideextending over the main pole and at least a portion of the non-magneticconductive structure. With the FGL disposed proximate to the main poleand over at least a portion of the non-magnetic conductive structure,current crowding and disturbance from the trailing shield are minimized.

The terms “over,” “under,” “between,” and “on” as used herein refer to arelative position of one layer with respect to other layers. As such,for example, one layer disposed over or under another layer may bedirectly in contact with the other layer or may have one or moreintervening layers. Moreover, one layer disposed between layers may bedirectly in contact with the two layers or may have one or moreintervening layers. In contrast, a first layer “on” a second layer is incontact with the second layer. Additionally, the relative position ofone layer with respect to other layers is provided assuming operationsare performed relative to a substrate without consideration of theabsolute orientation of the substrate.

FIG. 1 is a schematic illustration of a data storage device such as amagnetic media device. Such a data storage device may be a singledrive/device or comprise multiple drives/devices. For the sake ofillustration, a single disk drive 100 is shown according to oneembodiment. As shown, at least one rotatable magnetic disk 112 issupported on a spindle 114 and rotated by a drive motor 118. Themagnetic recording on each magnetic disk 112 is in the form of anysuitable patterns of data tracks, such as annular patterns of concentricdata tracks (not shown) on the magnetic disk 112.

At least one slider 113 is positioned near the magnetic disk 112, eachslider 113 supporting one or more magnetic head assemblies 121 that mayinclude an STO for applying an AC magnetic field to a disk surface 122and one or more non-magnetic conductive layers in contact with the STO.As the magnetic disk 112 rotates, the slider 113 moves radially in andout over the disk surface 122 so that the magnetic head assembly 121 mayaccess different tracks of the magnetic disk 112 where desired data arewritten. Each slider 113 is attached to an actuator arm 119 by way of asuspension 115. The suspension 115 provides a slight spring force whichbiases the slider 113 toward the disk surface 122. Each actuator arm 119is attached to an actuator means 127. The actuator means 127 as shown inFIG. 1 may be a voice coil motor (VCM). The VCM includes a coil movablewithin a fixed magnetic field, the direction and speed of the coilmovements being controlled by the motor current signals supplied bycontrol unit 129.

During operation of the disk drive 100, the rotation of the magneticdisk 112 generates an air bearing between the slider 113 and the disksurface 122 which exerts an upward force or lift on the slider 113. Theair bearing thus counter-balances the slight spring force of suspension115 and supports slider 113 off and slightly above the disk surface 122by a small, substantially constant spacing during normal operation.

The various components of the disk drive 100 are controlled in operationby control signals generated by control unit 129, such as access controlsignals and internal clock signals. Typically, the control unit 129comprises logic control circuits, storage means and a microprocessor.The control unit 129 generates control signals to control various systemoperations such as drive motor control signals on line 123 and headposition and seek control signals on line 128. The control signals online 128 provide the desired current profiles to optimally move andposition slider 113 to the desired data track on disk 112. Write andread signals are communicated to and from write and read heads on theassembly 121 by way of recording channel 125.

The above description of a typical magnetic media device and theaccompanying illustration of FIG. 1 are for representation purposesonly. It should be apparent that magnetic media devices may contain alarge number of media, or disks, and actuators, and each actuator maysupport a number of sliders.

FIG. 2 is a fragmented, cross-sectional side view of a MAMR read/writehead 200 facing a magnetic disk 202 according to one embodiment. TheMAMR read/write head 200 and the magnetic disk 202 may correspond to themagnetic head assembly 121 and the magnetic disk 112, respectively inFIG. 1. The read/write head 200 includes a media facing surface (MFS)212, such as an air bearing surface (ABS), facing the disk 202, amagnetic write head 210, and a magnetic read head 211. As shown in FIG.2, the magnetic disk 202 moves past the write head 210 in the directionindicated by the arrow 232 and the read/write head 200 moves in thedirection indicated by the arrow 234.

In some embodiments, the magnetic read head 211 is a magnetoresistive(MR) read head that includes an MR sensing element 204 located betweenMR shields S1 and S2. In other embodiments, the magnetic read head 211is a magnetic tunnel junction (MTJ) read head that includes a MTJsensing device 204 located between MR shields S1 and S2. The magneticfields of the adjacent magnetized regions in the magnetic disk 112 aredetectable by the MR (or MTJ) sensing element 204 as the recorded bits.

The write head 210 includes a main pole 220, a leading shield 206, atrailing shield 240, an STO 230 disposed between the main pole 220 andthe trailing shield 240, and a coil 218 that excites the main pole 220.The coil 218 may have a “pancake” structure which winds around aback-contact between the main pole 220 and the trailing shield 240,instead of a “helical” structure shown in FIG. 2. A dielectric material254, such as alumina, is located between the leading shield 206 and themain pole 220. The main pole 220 may be a magnetic material such as aFeCo alloy. The leading shield 206 and the trailing shield 240 may be amagnetic material, such as NiFe alloy.

The main pole 220, the trailing shield 240 and the STO 230 all extend tothe MFS 212. The STO 230 is electrically coupled to the main pole 220and the trailing shield 240. In some embodiment, a trailing shield hotseed layer 241 is coupled to the trailing shield 240, and the STO 230 iselectrically coupled to the trailing shield hot seed layer 241. Thetrailing shield hot seed layer 241 may include a high moment sputtermaterial, such as CoFeN or FeXN, where X includes at least one of Rh,Al, Ta, Zr, and Ti. The main pole 220 includes a trailing taper 242 anda leading taper 244. The trailing taper 242 extends from a locationrecessed from the MFS 212 to the MFS 212. The leading taper 244 extendsfrom a location recessed from the MFS 212 to the MFS 212. The trailingtaper 242 and the leading taper 244 may have the same degree of taper,and the degree of taper is measured with respect to a longitudinal axis260 of the main pole 220. In some embodiments, the main pole 220 doesnot include the trailing taper 242 and the leading taper 244. Instead,the main pole 220 includes a trailing side (not shown) and a leadingside (not shown), and the trailing side and the leading side aresubstantially parallel.

A non-magnetic conductive structure 250 is coupled to the main pole 220.The non-magnetic conductive structure 250 extends from the MFS 212 to alocation recessed from the MFS 212. The non-magnetic conductivestructure 250 and the STO 230 are described in detail in FIG. 3.

During operation, the STO 230 generates an AC magnetic field thattravels to the magnetic disk 202 to lower the coercivity of the regionof the magnetic disk 202 adjacent to the STO 230.

FIG. 3 is a MFS view of a portion of the write head 210 of FIG. 2according to one embodiment. As shown in FIG. 3, the write head 210includes the trailing shield 240, the main pole 220, the STO 230disposed between the trailing shield 240 and the main pole 220, anon-magnetic conductive structure 250 surrounding a portion of the mainpole 220, and a side shield 312 surrounding the non-magnetic conductivestructure 250. The definition of the term “surround” includes having anintermediate material between a first element that is surrounding asecond element and the second element that is being surrounded by thefirst element. For example, the dielectric material 254 is disposedbetween the non-magnetic conductive structure 250 and the side shield312.

The main pole 220 includes a surface 320 at the MFS 212. The surface 320includes a first side 322 in contact with the STO 230, a second side 324connected to the first side 322, and a third side 326 opposite thesecond side 324.

The non-magnetic conductive structure 250 is fabricated from anon-magnetic electrically conductive metal, such as NiTa, Cr, Cu, or Rh.In some embodiments, the non-magnetic conductive structure 250 isfabricated from a multi-layer stack, such as NiTa/Ru, Cr/Cu, or Cr/Rh.The non-magnetic conductive structure 250 surrounds a portion of themain pole 220 at the MFS 212. For example, the non-magnetic conductivestructure 250 surrounds the second side 324 and the third side 326 ofthe main pole 220. In one embodiment, the non-magnetic conductivestructure 250 includes a first portion 314 and a second portion 316. Thefirst portion 314 is in contact with the second side 324 of the mainpole 220, and the second portion 316 is in contact with the third side326 of the main pole 220. In one embodiment, the first portion 314 andthe second portion 316 are fabricated from the same non-magneticconductive material. In other embodiments, the first portion 314 and thesecond portion 316 are fabricated from different non-magnetic conductivematerials.

The STO 230 includes an underlayer 302, an FGL 304 disposed on theunderlayer 302, an interlayer 306 disposed on the FGL 304, an SPL 308disposed on the interlayer 306, and a cap layer 310 disposed on the SPL308. The SPL 308 may be a CoNi layer having perpendicular magneticanisotropy. Other materials may be used as the SPL 308, such as CoPt,CoCrPt, CoPd, FePt, CoFePd, CrMo, TbFeCo, or combinations thereof. TheFGL 304 may be CoFe, CoFeHo, or combinations thereof. The interlayer 306may be a metal layer having long spin diffusion length such as Au, Ag,or Cu, when the STO 230 employs current perpendicular to plane (CPP)giant magnetoresistance (GMR). The cap layer 310 is an electricalconductive layer, such as a Ru/Ta/Ru multi-layer stack. The underlayer302 includes the surface 321 at the MFS. The surface 321 includes a side319 in contact with the main pole 220 and the non-magnetic conductivestructure 250.

The first side 322 of the main pole 220 has a length L1 in thecross-track direction, as indicated by the X-axis. The side 319 of thesurface 321 of the underlayer 302 has a length L2 in the cross-trackdirection, as indicated by the X-axis. The length L2 of the side 319 ofthe underlayer 302 is substantially greater than the length L1 of thefirst side 322 of the main pole 220. The FGL 304 includes a surface 303at the MFS 212. The surface 303 has a first side 305 and a second side307 opposite the first side 305. The first side 305 of the FGL 304 facesthe main pole 220 and the non-magnetic conductive structure 250, and thesecond side 307 faces the SPL 308. The definition of the term “face” isextended to include a material located between a first element that isfacing a second element and the second element. For example, theunderlayer 302 is located between the FGL 304 and the main pole 220 (andthe non-magnetic conductive structure 250). The first side 305 is incontact with the underlayer 302, and the second side 307 is in contactwith the interlayer 306. The first side 305 of the FGL 304 has a lengthL3 in the cross-track direction, and the second side 307 of the FGL 304has a length L4 in the cross-track direction. The length L3 of the firstside 305 is substantially greater than the length L1 of the first side322 of the main pole 220. In one embodiment, the length L3 of the firstside 305 is substantially less than the length L2 of the side 319 of theunderlayer 302. In another embodiment, the length L3 of the first side305 is substantially the same as the length L2 of the side 319 of theunderlayer 302. In one embodiment, the length L4 of the second side 307is substantially the same as the length L1 of the first side 322 of themain pole 220.

The first portion 314 of the non-magnetic conductive structure 250includes a surface 330 at the MFS 212. The second portion 316 of thenon-magnetic conductive structure 250 includes a surface 332 at the MFS212. The surface 330 of the non-magnetic conductive structure 250includes a side 313 in contact with the STO 230. The surface 332 of thenon-magnetic conductive structure 250 includes a side 315 in contactwith the STO 230. The side 313 of the non-magnetic conductive structure250 has a length L5 in the cross-track direction, as indicated by theX-axis. The side 315 of the non-magnetic conductive structure 250 has alength L6 in the cross-track direction, as indicated by the X-axis. Inone embodiment, the length L5 is substantially the same as the lengthL6. In one embodiment, the sum of the length L5 and the length L6 issubstantially greater than the length L1 of the side 322 of the mainpole 220. In one embodiment, the sum of the length L5, the length L6,and the length L1 is substantially the same as the length L2 of the side319 of the STO 230. In one embodiment, the length L3 of the side 305 ofthe FGL 304 is substantially less than the sum of the length L5, thelength L6, and the length L1 and substantially greater than the sum ofthe length L1 and one of the lengths L5 and L6.

Because the non-magnetic conductive structure 250 is in contact with themain pole 220, the current flowing to the STO 230 from the main pole 220and the non-magnetic conductive structure 250 is more uniform. Thenon-magnetic conductive structure 250 helps spread the electricalcurrent to the STO 230 from the main pole 220. In one embodiment, themain pole 220 and the non-magnetic conductive structure 250 areconnected to the same current source.

One or multiple current sources may be used to provide a current flowingto the STO 230 from the main pole 220 and a current flowing to the STO230 from the non-magnetic conductive structure 250. When multiplecurrent sources are used, the current uniformity can be furthercontrolled by controlling the multiple current sources. The non-magneticconductive structure 250 provides additional paths for electricalcurrents to flow to the STO 230. The non-magnetic conductive structure250 enables higher current density to the STO 230 without creating hotspots at the MFS 212. Maximum current efficiency and uniformity can beachieved with the non-magnetic conductive structure 250.

FIGS. 4A-4C are MFS views of the STO 230 of the write head 210 of FIG. 2according to one embodiment. The STO 230 includes the underlayer 302,the FGL 304, the interlayer 306, the SPL 308, and the cap layer 310. Asshown in FIG. 4A, the length L2 of the side 319 of the underlayer 302 issubstantially the same as the length L3 of the side 305 of the FGL 304.The FGL 304 includes the surface 303 at the MFS 212. The surface 303includes the first side 305, the second side 307, a third side 404connecting the first side 305 and the second side 307, and a fourth side406 opposite the third side 404. The surface 303 has a trapezoidalshape, as shown in FIG. 4A, and the trapezoidal shaped surface 303includes two acute angles 8. The acute angles 8 may be greater thanabout 38 degrees, such as between about 38 degrees and about 85 degrees.The angles 8 is formed between the side 305 and the side 404 or 406. Theangle formed between the side 305 and the side 404 may not be the sameas the angle formed between the side 305 and the side 406. The SPL 308includes a surface 408 at the MFS 212. The surface 408 of the SPL 308has a rectangular shape.

As shown in FIG. 4B, the length L2 of the side 319 of the underlayer 302is substantially greater than the length L3 of the side 305 of the FGL304. The FGL 304 includes the trapezoidal shaped surface 303 having twoacute angles 8 at the MFS 212. The SPL 308 includes the rectangularshaped surface 408 at the MFS 212.

As shown in FIG. 4C, the STO 230 includes the underlayer 302, a firstmagnetic layer 410 disposed on the underlayer 302, the interlayer 306disposed on the first magnetic layer 410, a second magnetic layer 412disposed on the interlayer 306, and the cap layer 310 disposed on thesecond magnetic layer 412. In one embodiment, the first magnetic layer410 is the FGL having the trapezoidal shaped surface at the MFS 212, andthe second magnetic layer 412 is the SPL having the rectangular shapedsurface at the MFS 212. The FGL is located proximate to the main pole220 (FIG. 3), and the SPL is located proximate to the trailing shield240 (FIG. 3). In another embodiment, the first magnetic layer 410 is theSPL having the trapezoidal shaped surface at the MFS 212, and the secondmagnetic layer 412 is the FGL having the rectangular shaped surface atthe MFS 212. The SPL is located proximate to the main pole 220 (FIG. 3),and the FGL is located proximate to the trailing shield 240 (FIG. 3). Inanother embodiment, both the first and second magnetic layers 410, 412have rectangular shaped surfaces at the MFS 212.

With various configurations of the STO 230, different types ofoscillation by the STO 230 can be achieved. FIGS. 5A-5D illustratevarious ways one or more electrical currents can flow through the STO230 using one current source. FIGS. 6A-6C illustrate various ways one ormore electrical currents can flow through the STO 230 using two currentsources.

FIGS. 5A-5D are cross-sectional side views of the write head 210 of FIG.2 according to one embodiment. The dielectric material 254 is omitted inFIGS. 5A-5D for better illustration. As shown in FIG. 5A, the write head210 includes a current source 502 connected to the main pole 220 and thetrailing shield 240. A current I₁ generated from the current source 502flows from the main pole 220 to the trailing shield 240 through the STO230. In one embodiment, the current I₁ flows from the trailing shield240 to the main pole 220 through the STO 230.

As shown in FIG. 5B, the current source 502 is connected to the mainpole 220, the trailing shield 240, and the leading shield 206. Inaddition to the current I₁, a second current I₂ flows from the main pole220 to the leading shield 206 through the non-magnetic conductivestructure 250. As current flows through the non-magnetic conductivestructure 250, write-ability of the write head 210 is improved. In oneembodiment, the FGL of the STO 230 is located proximate to the main pole220, and the current I₁ flows from the main pole 220 to the trailingshield 240 through the STO 230, as shown in FIG. 5B. In anotherembodiment, the FGL of the STO 230 is located proximate to the trailingshield 240, and the current I₁ flows from the trailing shield 240 to themain pole 220 through the STO 230. In one embodiment, the STO 230 is notpresent, and write-ability is improved by flowing the current I₂ throughthe non-magnetic conductive structure 250.

As shown in FIG. 5C, a non-magnetic conductive layer 504 is disposedbetween the main pole 220 and the trailing shield 240 at a locationrecessed from the MFS 212. The non-magnetic conductive layer 504 may befabricated from the same material as the non-magnetic conductivestructure 250. A dielectric layer 506 is disposed between the STO 230and the non-magnetic conductive layer 504. The dielectric layer 506 maybe fabricated from the same material as the dielectric material 254. Adielectric layer 508 is disposed between a portion of the non-magneticconductive layer 504 and a portion of the main pole 220. The dielectriclayer 508 may be fabricated from the same material as the dielectricmaterial 254. The current source 502 is connected to the main pole 220and the trailing shield 240. In addition to the current I₁, a secondcurrent I₃ flows from the main pole 220 to the trailing shield 240through the non-magnetic conductive layer 504. As current flows throughthe non-magnetic conductive layer 504, write-ability of the write head210 is improved. In one embodiment, the FGL of the STO 230 is locatedproximate to the main pole 220, the current I₁ flows from the main pole220 to the trailing shield 240 through the STO 230, and the current I₃flows from the main pole 220 to the trailing shield 240 through thenon-magnetic conductive layer 504, as shown in FIG. 5C. In anotherembodiment, the FGL of the STO 230 is located proximate to the trailingshield 240, the current I₁ flows from the trailing shield 240 to themain pole 220 through the STO 230, and the current I₃ flows from thetrailing shield 240 to the main pole 220 through the non-magneticconductive layer 504. In one embodiment, the STO 230 and the dielectriclayer 506 are not present, and the non-magnetic conductive layer 504extends to the MFS 212.

As shown in FIG. 5D, the current source 502 is connected to the mainpole 220, the trailing shield 240, and the leading shield 206. CurrentI₁ flows from the main pole 220 to the trailing shield 240 through theSTO 230, current I₂ flows from the main pole 220 to the leading shield206 through the non-magnetic conductive structure 250, and current I₃flows from the main pole 220 to the leading shield 206 through thenon-magnetic conductive layer 504. In one embodiment, the FGL of the STO230 is located proximate to the main pole 220, the current I₁ flows fromthe main pole 220 to the trailing shield 240 through the STO 230, andthe current I₃ flows from the main pole 220 to the trailing shield 240through the non-magnetic conductive layer 504, as shown in FIG. 5D. Inanother embodiment, the FGL of the STO 230 is located proximate to thetrailing shield 240, the current I₁ flows from the trailing shield 240to the main pole 220 through the STO 230, and the current I₃ flows fromthe trailing shield 240 to the main pole 220 through the non-magneticconductive layer 504. In one embodiment, the STO 230 and the dielectriclayer 506 are not present, and the non-magnetic conductive layer 504extends to the MFS 212. The operations of the current source 502 arecontrolled by the control unit 129 (FIG. 1)

FIGS. 6A-6C are cross-sectional side views of the write head 210 of FIG.2 according to one embodiment. The dielectric material 254 is omitted inFIGS. 6A-6C for better illustration. As shown in FIG. 6A, the write head210 includes a first current source 602 connected to the main pole 220and the trailing shield 240 and a second current source 604 connected tothe main pole 220 and the leading shield 206. A current I₄ generatedfrom the current source 602 flows from the trailing shield 240 to themain pole 220 through the STO 230. A current I₅ generated from thecurrent source 604 flows from the leading shield 206 to the main pole220 through the non-magnetic conductive structure 250. In oneembodiment, the current I₄ flows from the main pole 220 to the trailingshield 240, and the current I₅ flows from the main pole 220 to theleading shield 206.

As shown in FIG. 6B, the current source 602 is connected to the mainpole 220 and the trailing shield 240. The current source 604 isconnected to the main pole 220, the leading shield 206, and thenon-magnetic conductive layer 504. A dielectric layer 606 is disposedbetween the STO 230 and the non-magnetic conductive layer 504, andbetween the trailing shield 240 and the non-magnetic conductive layer504. In addition to currents I₄ and I₅, a current I₆ flows from thenon-magnetic conductive layer 504 to the main pole 220. In oneembodiment, the current I₄ flows from the main pole 220 to the trailingshield 240, the current I₅ flows from the main pole 220 to the leadingshield 206, and the current I₆ flows from the main pole 220 to thenon-magnetic conductive layer 504. In one embodiment, the STO 230 andthe dielectric layer 606 are not present, and the non-magneticconductive layer 504 extends to the MFS 212.

As shown in FIG. 6C, the current source 602 is connected to the mainpole 220 and the trailing shield 240. The current source 604 isconnected to the main pole 220 and the non-magnetic conductive layer504. Current I₄ flows from the trailing shield 240 to the main pole 220through the STO 230. Current I₆ flows from the non-magnetic conductivelayer 504 to the main pole 220. In one embodiment, the current I₄ flowsfrom the main pole 220 to the trailing shield 240, and the current I₆flows from the main pole 220 to the non-magnetic conductive layer 504.In one embodiment, the STO 230 and the dielectric layer 606 are notpresent, and the non-magnetic conductive layer 504 extends to the MFS212. The operations of the current sources 602, 604 are controlled bythe control unit 129 (FIG. 1)

In summary, a MAMR enabled magnetic head is disclosed. The MAMR headincludes an STO in contact with a main pole and a non-magneticconductive structure surrounding the main pole. The STO includes an FGLproximate to the main pole, and the FGL has a trapezoidal shape at theMFS. The non-magnetic conductive structure and the trapezoidal shapedFGL provide additional paths for electrical currents to flow to the STOfrom the main pole and the non-magnetic conductive structure. Thenon-magnetic conductive structure and the trapezoidal shaped FGL enablehigher current density to the STO without creating hot spots at the MFS.Maximum current efficiency and uniformity can be achieved with thenon-magnetic conductive structure and the trapezoidal shaped FGL.

In one non-limiting embodiment, a magnetic recording head includes amain pole, and a spin torque oscillator in contact with the main pole.The spin torque oscillator includes a spin polarization layer and afield generation layer disposed between the spin polarization layer andthe main pole. The field generation layer includes a surface at a mediafacing surface, and the surface has a trapezoidal shape. The magneticrecording head further includes a non-magnetic conductive structuresurrounding at least a portion of the main pole, and the non-magneticconductive structure is in contact with the spin torque oscillator.

In another non-limiting embodiment, the magnetic recording head furtherincludes an underlayer in contact with the main pole and thenon-magnetic conductive structure, and the field generation layer isdisposed on the underlayer. The magnetic recording head further includesan interlayer disposed between the spin polarization layer and the fieldgeneration layer and a cap layer disposed on the spin polarizationlayer.

In another non-limiting embodiment, the non-magnetic conductivestructure includes a non-magnetic electrically conductive metal.

In another non-limiting embodiment, the non-magnetic conductivestructure further includes NiTa, Cr, Cu, or Rh.

In another non-limiting embodiment, the spin polarization layer includesa surface at the media facing surface, and the surface has a rectangularshape.

In another non-limiting embodiment, a data storage device includes themagnetic recording head.

In another non-limiting embodiment, a magnetic recording head includes amain pole, and a spin torque oscillator in contact with the main pole.The spin torque oscillator includes a spin polarization layer and afield generation layer disposed between the spin polarization layer andthe main pole. The field generation layer includes a surface at a mediafacing surface, and the surface includes a first side facing the mainpole and a second side facing the spin polarization layer. The firstside has a length that is substantially greater than a length of thesecond side. The magnetic recording head further includes a non-magneticconductive structure surrounding at least a portion of the main pole,and the first side of the field generation layer is disposed over atleast a portion of the non-magnetic conductive structure.

In another non-limiting embodiment, the spin torque oscillator furtherincludes an underlayer in contact with the main pole and thenon-magnetic conductive structure, and the field generation layer isdisposed on the underlayer.

In another non-limiting embodiment, the underlayer includes a surface atthe media facing surface, wherein the surface includes a side in contactwith the main pole and the non-magnetic conductive structure.

In another non-limiting embodiment, the side of the underlayer has alength substantially greater than the length of the first side of thefield generation layer.

In another non-limiting embodiment, the side of the underlayer has alength substantially the same as the length of the first side of thefield generation layer.

In another non-limiting embodiment, a magnetic recording head includes amain pole, and a spin torque oscillator in contact with the main pole.The spin torque oscillator includes a spin polarization layer and afield generation layer disposed between the spin polarization layer andthe main pole. The field generation layer includes a surface at a mediafacing surface, and the surface includes a first side facing the mainpole, a second side facing the spin polarization layer, a third sideconnecting the first side and the second side, and a fourth sideopposite the third side. The first side forms a first acute angle withthe third side. The magnetic recording head further includes anon-magnetic conductive structure surrounding at least a portion of themain pole, and the non-magnetic conductive structure is in contact withthe spin torque oscillator.

In another non-limiting embodiment, the first acute angle ranges fromabout 38 degrees to about 85 degrees.

In another non-limiting embodiment, the first side of the surface of thefield generation layer forms a second acute angle with the fourth side.

In another non-limiting embodiment, the second acute angle ranges fromabout 38 degrees to about 85 degrees.

In another non-limiting embodiment, the first acute angle and the secondacute angle are different.

In another non-limiting embodiment, a magnetic recording head includes aleading shield, a trailing shield, a main pole having a surface at amedia facing surface, wherein the surface includes a side, a spin torqueoscillator in contact with the side of the main pole, wherein the spintorque oscillator comprises a spin polarization layer and a fieldgeneration layer, a non-magnetic conductive structure surrounding atleast a portion of the main pole, a first current source connected tothe main pole and the trailing shield, and a second current sourceconnected to the main pole and the leading shield.

In another non-limiting embodiment, the first current source isconfigured to flow a first current from the main pole to the trailingshield through the spin torque oscillator, and the second current sourceis configured to flow a second current from the main pole to the leadingshield through the non-magnetic conductive structure.

In another non-limiting embodiment, the first current source isconfigured to flow a first current from the trailing shield to the mainpole through the spin torque oscillator, and the second current sourceis configured to flow a second current from the leading shield to themain pole through the non-magnetic conductive structure.

In another non-limiting embodiment, the magnetic recording head furtherincludes a non-magnetic conductive layer disposed between the trailingshield and the main pole.

In another non-limiting embodiment, the magnetic recording head furtherincludes a dielectric layer disposed between the spin torque oscillatorand the non-magnetic conductive layer and between the trailing shieldand the non-magnetic conductive layer.

In another non-limiting embodiment, the second current source isconnected to non-magnetic conductive layer.

In another non-limiting embodiment, the second current source isconfigured to flow a third current from the non-magnetic conductivelayer to the main pole.

In another non-limiting embodiment, a magnetic recording head includes aleading shield, a trailing shield, a main pole having a surface at amedia facing surface, wherein the surface includes a side, anon-magnetic conductive layer disposed between the trailing shield andthe main pole, a spin torque oscillator in contact with the side of themain pole, wherein the spin torque oscillator comprises a spinpolarization layer and a field generation layer, a non-magneticconductive structure surrounding at least a portion of the main pole,and a current source configured to flow a first current from the mainpole to the trailing shield through the spin torque oscillator and asecond current from the main pole to the trailing shield through thenon-magnetic conductive layer.

In another non-limiting embodiment, the current source is connected tothe main pole and the trailing shield.

In another non-limiting embodiment, the current source is connected tothe leading shield and is configured to flow a third current from themain pole to the leading shield through the non-magnetic conductivestructure.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

What is claimed is:
 1. A magnetic recording head, comprising: a leadingshield; a trailing shield; a main pole having a surface at a mediafacing surface, wherein the surface includes a side; a spin torqueoscillator in contact with the side of the main pole, wherein the spintorque oscillator comprises a spin polarization layer and a fieldgeneration layer; a non-magnetic conductive structure surrounding atleast a portion of the main pole; a first current source connected tothe main pole and the trailing shield; and a second current sourceconnected to the main pole and the leading shield.
 2. The magneticrecording head of claim 1, wherein the first current source isconfigured to flow a first current from the main pole to the trailingshield through the spin torque oscillator, and the second current sourceis configured to flow a second current from the main pole to the leadingshield through the non-magnetic conductive structure.
 3. The magneticrecording head of claim 1, wherein the first current source isconfigured to flow a first current from the trailing shield to the mainpole through the spin torque oscillator, and the second current sourceis configured to flow a second current from the leading shield to themain pole through the non-magnetic conductive structure.
 4. The magneticrecording head of claim 1, further comprising a non-magnetic conductivelayer disposed between the trailing shield and the main pole.
 5. Themagnetic recording head of claim 4, further comprising a dielectriclayer disposed between the spin torque oscillator and the non-magneticconductive layer and between the trailing shield and the non-magneticconductive layer.
 6. The magnetic recording head of claim 1, wherein thesecond current source is connected to non-magnetic conductive layer. 7.The magnetic recording head of claim 6, wherein the second currentsource is configured to flow a third current from the non-magneticconductive layer to the main pole.
 8. A data storage device comprisingthe magnetic recording head of claim
 1. 9. A magnetic recording head,comprising: a leading shield; a trailing shield; a main pole having asurface at a media facing surface, wherein the surface includes a side;a spin torque oscillator in contact with the side of the main pole,wherein the spin torque oscillator comprises a spin polarization layerand a field generation layer; a non-magnetic conductive structuresurrounding at least a portion of the main pole; a first current sourceconnected to the main pole and the trailing shield; and a second currentsource connected to the main pole, the non-magnetic conductivestructure, and the leading shield.
 10. The magnetic recording head ofclaim 9, wherein the non-magnetic conductive structure comprises anon-magnetic electrically conductive metal.
 11. The magnetic recordinghead of claim 10, wherein the non-magnetic conductive structure furthercomprises NiTa, Cr, Cu, or Rh.
 12. The magnetic recording head of claim9, wherein the spin polarization layer includes a surface at the mediafacing surface, wherein the surface has a rectangular shape.
 13. Themagnetic recording head of claim 9, wherein the spin torque oscillatorfurther comprises an underlayer in contact with the main pole and thenon-magnetic conductive structure, wherein the field generation layer isdisposed on the underlayer.
 14. The magnetic recording head of claim 13,wherein the underlayer includes a surface at the media facing surface,wherein the surface includes a side in contact with the main pole andthe non-magnetic conductive structure.
 15. The magnetic recording headof claim 14, wherein the side of the underlayer has a lengthsubstantially greater than the length of a side of the field generationlayer.
 16. The magnetic recording head of claim 14, wherein the side ofthe underlayer has a length substantially the same as the length of theside of the field generation layer.
 17. A data storage device comprisingthe magnetic recording head of claim
 9. 18. A magnetic recording head,comprising: a leading shield; a trailing shield; a main pole having asurface at a media facing surface, wherein the surface includes a side;a spin torque oscillator in contact with the side of the main pole,wherein the spin torque oscillator comprises a spin polarization layerand a field generation layer; a non-magnetic conductive structuresurrounding at least a portion of the main pole; a first current sourceconnected to the main pole and the trailing shield; and a second currentsource connected to the main pole and the non-magnetic conductivestructure.
 19. The magnetic recording head of claim 18, wherein thenon-magnetic conductive structure comprises NiTa, Cr, Cu, or Rh, whereinthe spin torque oscillator further comprises an underlayer in contactwith the main pole and the non-magnetic conductive structure, whereinthe field generation layer is disposed on the underlayer, and whereinthe underlayer includes a surface at the media facing surface, whereinthe surface includes a side in contact with the main pole and thenon-magnetic conductive structure.
 20. A data storage device comprisingthe magnetic recording head of claim 18.